Abaqus CPT with cohesion.

Hi all...

I am new to abaqus. I have to model cone penetration test (CPT) in abaqus.

I am using drucker prager plasticity and hardening to model the soil.

The cohesion (d) decreases as plastic strain increases. But how do i input this into the model ?

Drucker prager hardening inputs have yield stress and plastic strain columns.

So from cohesion, how do i get the yield stress values ?